Plasma electrolytic cell

ABSTRACT

Electrolytic devices, including electrolytic cells, are described, that can be used in various segments of technology for the production of hydrogen and oxygen by electrolysis of water electrolytes. In one embodiment, a plasma electrolytic cell is provided, comprising an anode and a cathode located in dielectric containers interconnected via a pipe in their bottom portions, wherein the spiral shaped cathode is made from electrically insulated copper wire and the electric insulation has local breaks, wherein the anode is planar, the cathode and anode containers have covers with embedded gas pressure adjustment valves, wherein the top portions of the containers are connected to gas offtake devices, and wherein the cathode and anode containers allow adding more electrolyte.

CROSS-REFERENCE TO RELATED APPLICATION

The instant application is a continuation-in-part of PCT International Patent Application Serial No. PCT/RU2012/000164, filed Mar. 6, 2012, pending, which claims priority to Russian Patent Application Serial No. 2011127344, filed Jul. 5, 2011, pending, the entire specifications of both of which are expressly incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to electrolytic devices, more specifically, to electrolytic cells, and can be used in various segments of technology for the production of hydrogen and oxygen by electrolysis of water electrolytes.

BACKGROUND OF THE INVENTION

RU Patent 2149921 discloses an electrolytic cell for the electrolysis of water comprising multiple electrodes in the form of a pile that form the anode, wherein each anodic electrode consists of a flat plate, multiple electrodes in the form of a pile that form the cathode, wherein each cathodic electrode consists of a flat plate, and the anodic electrodes interchange with the cathodic electrodes. Furthermore, the electrolytic cell comprises at least one first conducting connecting element passing through the interchanging anodes and providing for electrical connection only with each anodic electrode and at least one second conducting connecting element passing through the interchanging cathodes and providing for electrical connection only with each cathodic electrode.

Disadvantages of the known electrolytic cell for the production of hydrogen and oxygen gases for use in welding are its complex design and low efficiency.

RU Patent 2228390 discloses a device for the production of heat power, hydrogen and oxygen comprising a case made from a dielectric material, a cover, anode and cathode cavities, a planar ring anode with openings located in the anode cavity and connected to the positive pole of the power source, a cathode in the form of a rod of a refractory material inserted into a dielectric tube with outer thread and connected to the negative pole of the power source, and a working solution supply port located in the middle portion of the anode cavity, wherein the cover is made from a dielectric material and has a cylinder-conic extension with a through opening forming the anode and cathode cavities jointly with the case, the dielectric tube is inserted into the inter-electrode chamber by means of its outer thread through a threaded opening in the case and centered in the through opening of the cover that forms the top cathode cavity, the anode cavity is interconnected with the top cathode cavity via a channel consisting of a vertical section and a horizontal section located in the cover, further wherein the gap between the top and the bottom cathode cavities is set adjustable by moving the dielectric tube. The device further comprises a working solution drainage port located at a side of the cover and a gas mixture output port located in the top portion of the cover coaxially with the top cathode cavity, and the cathode and anode are connected to the power unit consisting of a pulse generator and a control circuit.

Disadvantages of the known device are its complex design and low efficiency.

The closest counterpart of the technical solution provided herein is RU Patent 2175027 that discloses a device for the production of heat power, hydrogen and oxygen comprising a case made from a dielectric material and having a through opening, an inter-electrode chamber, working solution supply and drainage ports, an anode connected to the positive pole of the power source and a cathode connected to the negative pole of the power source. The case with an axial opening comprises a bottom cylinder-conic extension and a bottom cover forming jointly with the case the inter-electrode chamber consisting of an anode cavity and a cathode cavity interconnected in the bottom section. A planar ring anode with openings is located in the anode cavity. The cathode is in the form of a rod of a refractory material inserted into a threaded dielectric tube. The dielectric tube is inserted into the inter-electrode chamber via a threaded opening in the bottom cover and can be moved in the vertical direction along the axial line of the device. The working solution container with an automatic solution level control system in the cathode cavity is connected with the anode cavity. The device also comprises a cooling chamber for steam condensation and hydrogen separation the cavity of which is interconnected with the working solution supply port of the anode cavity. A vapor/gas mixture supply port of the cooling chamber is inserted by means of its thread into the case opening, and an oxygen output port is inserted into the top portion of the anode cavity.

The known device operates as follows.

The working solution is poured into a container from which is passes through a batching device and a float chamber to the anode cavity and the cathode cavity. After the required solution level in the reactor is achieved, the float of the float chamber closes the intake opening of the batching device. Then power is supplied, and the voltage is gradually increased until the generation of stable plasma in the cathode zone. The vapor/gas mixture produced at the cathode is supplied to the cooler. The steam exposed to the cold surface of the cooler pipe condenses, and the released gas emanates from under the reflector to the output port. Steam condensate is supplied to the anode cavity via a tube and the intake port. Oxygen released at the anode is supplied to the top portion of the anode cavity and is removed via a port. As the solution level in the reactor is controlled automatically, this hydrogen and oxygen production device operates automatically as well. As the working solution is consumed, it is replenished in the receiver container.

The nature of the physicochemical processes occurring in the reactor is that an electric field between the cathode and the anode where the cathode area is far smaller than that of the anode produces the initial cathode-focused ion flux of the alkaline metal present in the electrolyte. Due to a reserve of kinetic energy accumulated during cathode-oriented movement, the alkaline metal ions push hydrogen atoms from water molecules. Having reached the cathode, protons acquire electrons to form hydrogen atoms and emanate photons that form atomic hydrogen plasma at 5000-10,000° C. The energy of this plasma drives the thermal dissociation of water into hydrogen and oxygen and a release of additional energy which is easily indicated by the increased energy of the heated solution, evaporated water and collected gases. Electrolytic hydrogen release occurs simultaneously at the anode. Thus, the hydrogen plasma at the cathode is the source of thermal energy transferred to the water solution and simultaneously the source of atomic and molecular hydrogen and oxygen.

Disadvantage of the known technical solution is that the cathode is permanently inside the plasma zone dramatically reducing its service life. Furthermore, the device has quite a complex design.

BRIEF DESCRIPTION OF THE DRAWINGS

The FIGURE illustrates a schematic view of a plasma electrolytic cell in accordance with the general teachings of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The object of this invention is to provide an efficient electrolytic cell for water decomposition into hydrogen and oxygen.

It is suggested to achieve the objective by using the plasma electrolytic cell having the design provided herein. The plasma electrolytic cell comprises an anode and a cathode located in dielectric containers interconnected via a pipe in their bottom portions. The spiral shaped cathode is made from electrically insulated copper wire wherein the electric insulation has local breaks, the anode is planar, the cathode and anode containers have covers with embedded gas pressure adjustment valves, the top portions of the containers are connected to gas offtake devices, and the cathode and anode containers allow adding more electrolyte. In some embodiments of this invention, cathode electric insulation is removed to form a stepwise pattern with 4 to 6 mm wide strips spaced 20 to 60 mm. However, other options of insulation removal from the cathode surface exist. The cathode preferably fills the cathode container. In some embodiments of this invention, the electrolytic cell allows adding more portions of electrolyte to the bottom parts of the cathode and anode containers.

The operation principle of the device provided herein is the same as the operation principle of the technical solution used as the closest counterpart. The technical solution provided herein allows producing hydrogen and oxygen from water electrolyte by plasma electrolysis and simultaneous separation of the gases. Plasma electrolysis is achieved by using a cathode providing for solution exposure of only some of its working zones that are not insulated from the electrolyte. This eliminates a single concentration area of high temperature plasma and allows distributing the heat load across a greater area of the cathode.

This dramatically reduces the heat load on the cathode and significantly increases its service life. Pulsed plasma formation in different cathode areas produces current pulses the average magnitude of which is far smaller than that reached when direct voltage and current are used for water electrolysis. This noticeably reduces the power consumption of electrolysis.

Furthermore, separate production of hydrogen and oxygen is achieved by placing the cathode and the anode in different containers the solutions of which are only interconnected in the bottom portions of the containers via a small diameter pipe.

The cathode located in the cathode container is preferably made from spiral shaped lacquer insulated copper wire. Homogeneous heat load distribution on the cathode is achieved by incomplete removal of cathode insulation to form intervals preferably less than 5 mm long and spaced 3-5 cm (see drawing zones a, b, c, d, e).

The anode is located in the anode container and has a plate-like shape.

Hydrogen released at the cathode leaves the cathode container through a valve that adjusts the pressure in the cathode container, and oxygen leaves through the valve and the port in the top cover of the anode container.

The basic embodiment of plasma electrolytic cell is designed as follows. Referring to the FIGURE, the plasma electrolytic cell comprises two dielectric containers, the cathode one 1 and the anode one 2 interconnected in the bottom portion with the dielectric pipe 3. The cathode and anode containers are connected to the common container 4 via the pipes 5 and 6 through which they are replenished with electrolyte.

The cathode 7 is made from lacquer insulated copper from which the insulation is removed so as to form intervals up to 5 mm long and spaced 3-5 cm (see zones a, b, c, d, e). The cathode has a spiral shape. The anode 8 has a plate-like shape and is made from an electrically conducting metal. The cathode container 1 and the anode container 2 have the covers 9 and 10 in which the valves 11 and 12 are installed that adjust the pressure in the cathode and anode containers.

Hydrogen leaves the cathode container 1 through the valve 11 and the pipe 13 which directs it to a standard dryer (not shown). Oxygen leaves the anode container through the valve 12 and the pipe 14 which directs it to a standard dryer (not shown).

The plasma electrolytic cell operates as follows. After the container 4 and the containers 1 and 2 are filled with electrolyte, power is supplied to the clamps 15 and 16, and the electrolyte starts heating. Gas release rate increases gradually, and when the solution temperature reaches the critical threshold, plasma pulses are generated at uninsulated cathode surface strips, and gas release rate increases dramatically, by decades of times, to reach 0.3-0.5 l/s. Correctly adjusted valves of the cathode and anode containers maintain the required solution level in each of the containers. The current amplitude varies randomly during that period, but its average value remains relatively low, and this saves electricity. The service life of the cathode increases by decades of times as a result. 

What is claimed is:
 1. A plasma electrolytic cell, comprising: an anode and a cathode located in dielectric containers interconnected via a pipe in their bottom portions; wherein the spiral shaped cathode is made from electrically insulated copper wire and the electric insulation has local breaks; wherein the anode is planar, the cathode and anode containers have covers with embedded gas pressure adjustment valves; wherein the top portions of the containers are connected to gas offtake devices; and wherein the cathode and anode containers allow adding more electrolyte.
 2. The plasma electrolytic cell of claim 1, wherein the cathode electric insulation is removed to form a stepwise pattern with 4 to 6 mm wide strips spaced 20 to 60 mm.
 3. The plasma electrolytic cell of claim 1, wherein the cathode substantially fills the cathode container.
 4. The plasma electrolytic cell of claim 1, wherein the electrolytic cell allows adding more portions of electrolyte to the bottom parts of the cathode and anode containers. 